31.
정현파 교류전압 e₁(t)과 e₂(t)의 합(e₁(t)＋e₂(t))은 몇 V인가?
$e_1(t) = 10\sqrt{2} \sin(\omega t + \frac{\pi}{3}) (V)$
$e_2(t) = 20\sqrt{2} \cos(\omega t
-
\frac{\pi}{6}) (V)$
①
30√2 sin(ωt + π/3)
②
30√2 sin(ωt - π/3)
③
10√2 sin(ωt + 2π/3)
④
10√2 sin(ωt - 2π/3)